Optional global timeout via system property
- different global timeout strategy variants can be useful:
(a) should the global timeout conditionally override specific test timeouts that are higher then the global timeout: to make sure a maximum test duration is not exceeded; also allows to test that something really must be very quick
(b) should a specific timeout always override the global timeout: e.g. to avoid the need to increase the global timeout, just because a single test takes longer
Now with test for variant (a)